Rubber crimping device



Oct. 18, 1960 R. J. MCMANUS RUBBER CRIMPING DEVICE;

2 Sheets-Sheet 1 Filed May 23, 1958 INVENTOR. RICHARD J. MCMANUS 7r 5. MM,

ciJQW Oct. 18, 1960 R. J. MCMANUS RUBBER CRIMPING DEVICE I 2 Sheets-Sheet 2 Filed May 23, 1958 INVENTOR. RICHARD J. MCMANUS amifi fi fl 4 BY elf-MM,

ATTORNEYS= United tates Patent RUBBER CRHVIPING DEVICE Richard J. McManus, Palmyra, N.J., assignor to the United States of America as represented by the Secretary of the Army Filed May 23, 1958, Ser. No. 737,459

3 Claims. (CI. 8639)' (Granted under Title 35, US. Code (1952), see. 266) The invention described herein may be manufactured and used by or for the Government for governmental purposes without the payment of any royalty thereon.

The invention relates to crimping devices and more especially to a liquid pressure device for crimping a casing into a groove surrounding the base of a projectile.

Conventional methods of assembling a cartridge case and projectile have heretofore involved the use of (1) a bar type tool which rolls the case into the projectile groove, (2) a collet type crimping fixture which exerts pressure against the case to squeeze the case into the groove, or (3) a fixture that presses the case into the groove by indenting in several places producing what is commonly called a stab crimp. All these methods have the objection that they mar and abrade the surface of the casing, producing hardened spots and facilitating erosion especially in the case of aluminum casings.

In accordance with the present invention these undesirable results are avoided by the provision of a satisfactory crimping device designed to apply a pressure which is equally distributed throughout the area to be crimped. Crimping devices of this type have the additional advantage that a number of them may be operated simultaneously from a single source of liquid pressure.

In the drawing Fig. 1 is a longitudinal section through a preferred embodiment of the present crimping device.

Fig. 2 is a section on the line 22 of Fig. 1 but with the piston and spring omitted.

Fig. 3 is a right side view of a clamp without the bolts in place.

Fig. 1 of the drawing shows a base having at one end an upright 11 which supports one end of a casing 12 and at the other end a crimping device into which the casing extends. Beyond the end of the casing 12 is a projectile 13 having a rotating ring 14, and surrounded at its base by a groove (not visible) into which the casing is to be crimped.

The crimping device includes a ring 15 of U-shaped cross-section made of an elastic material such as rubber. Surrounding this ring and protruding into it is an extension 16a of a cylinder block 16. A pair of clamp blocks 17 and 18 serve to clamp the outer rims of the ring 15 against the cylinder block extension 16a.

Movable within the cylinder block 16 is a piston 19 which has a leather cup 20 at its inner end and is constituted by a headed bolt or screw 20a and nut 20b clamping the base of said cup 20 against the piston 19 to reduce leakage past the piston, which is axially perforated to allow the removal of air from the cylinder. This perforation is normally closed at its outer end by a ball 21 which is fixed in place by a screw 22. A spring 23 is arranged to return the piston 19 to its rest position. The crimping pressure is applied to the ring 15 through any appropriate hydraulic pressure fluid such as oil or the like. The bolts between the clamping blocks 17 and 18 have heads 24 at one end and nuts 25 at the other end to obtain the desired clamping pressure on the outer sides of the elastic ring 15. The bolts are located at a convenient radial distance from ring 15 as is within the ability of one Patented Oct. 18, 1960 skilled in the art. A passageway 26 in extension 16a is for prmsure fluid under the piston 19 to be moved into the ring 15. Any convenient stop or abutment 27 limits upward movement of the piston under action of the spring 23.

The cylinder 16 with its extension 16a together with the ring 15 of U shaped cross-section is shown in Fig. 2 with the piston 19 and spring 23 removed. The particular shape is not critical so long as the herein mentioned advantages and features are preserved.

Fig. 3 merely shows a clamp block 18 as viewed from the right in Fig. 1 separate and apart from the apparatus described.

As will be apparent to those skilled in the art, the crimping device of this invention has the important advantage that there is no necessity of maintaining close tolerancing on the position of the groove for crimping purposes. Thus the groove may be placed in any desired location within the limits of the flexible ring. This simplifies the manufacturing process. It also permits the crimping of the casing into a multiplicity of grooves. Another advantage is a reduced tendency for leakage of liquid under pressure from the cylinder block 16 by the construction described. Those skilled in this art will understand that with the bolts 24 disclosed it may be possible to apply any desired pressure to the clamping plates 17 and 18 independently of the crimping pressure.

I claim:

1. In a device for crimping a easing into a groove surrounding the base of a projectile, the combination there with of a ring of flexible material of U-shaped cross section, a cylinder block having an extension arranged to surround and extend into and between the side walls of said ring, said extension having a passageway between the inside of said cylinder block and ring of flexible material, through which fluid pressure may be transferred to said ring for crimping, a pair of clamp blocks arranged to clamp the outer side faces of said flexible ring material against opposite sides of said extension, means including a piston movable within said cylinder block for applying pressure for crimping said casing into the projectile groove, and means for supporting a base of said casing as the casing is cn'mped into a groove.

2. A crimping device according to claim 1 in which said cylinder block contains a movable piston, and a spring between the piston and an end portion of said cylinder block for moving said piston in one direction.

3. In a device for crimping a. cartridge case into a groove on a projectile to which said case is to be attached, said device including a fluid pressure cylinder and a flexible ring of U-shaped cross section extending around said projectile and casing for pressing said case into said groove under fluid pressure from said cylinder, the combination therewith of the improvement for reducing the likelihood of leakage from said ring of U-shaped cross section, said improvement including an extension from said cylinder into said flexible ring and extending around said projectile and case substantially coaxially with said cartridge case and projectile, and clamping blocks pressing outer faces of side walls of said flexible ring longitudinally of the projectile and cartridge case against opposite outer sides of said extension, said extension being provided with an opening connecting said cylinder pressure with the flexible ring.

References Cited in the file of this patent UNITED STATES PATENTS 2,375,599 Walton May 8, 1945 2,423,862 Vorobik July 15, 1947 2,783,727 Hoffman Mar. 5, 1957 2,878,767 Paulton Mar. 24, 1959 

